1. Field of the Invention
The present invention relates generally to heat dissipation devices, and more particularly to a heat dissipation device having a rotatable fastener for securing a heat sink to a heat-generating component such as a central processing unit (CPU) mounted on a printed circuit board.
2. Description of Related Art
It is widely acknowledged that heat is produced during operations of electronic devices such as central processing units (CPUs). The produced heat must be quickly removed to ensure the CPUs working normally. Typically, a heat sink is disposed on the CPU to dissipate the heat therefrom.
In earlier times, linear-type locking devices were widely used for securing of heat sinks. A linear-type locking device, which is integrally made from a resilient metal wire, generally includes an elongated central pressing portion and a pair of locking arms extending from opposite ends of the elongated central pressing portion in opposite directions to thereby form a Z-shaped configuration. When assembled, the elongated central pressing portion of the linear-type locking device lodges in a heat sink, and the locking arms thereof are then resiliently deflected downwardly to engage with positioning means provided on a frame or socket to thereby secure the heat sink to a CPU. An example of a linear-type locking device is shown in U.S. Pat. No. 5,386,338. However, a linear-type locking device generally has a slim structure; it cannot firmly secure a heat sink to a CPU, especially nowadays the heat sink being made bigger and heavier aiming to obtain a high heat dissipating capacity. The linear-type locking device cannot securely fasten such a large and heavy heat sink to the CPU when the heat sink is subject to a vibration.
Thus, an improved locking device which overcomes above-mentioned problems is required.